<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>实现1到100相加求和</title>
</head>
<body>
    <script>
        var a = 1;
        var sum = 0;
        while ( a<=100 ){
           sum += a;
           a ++ ;
        }
        alert("1-100的数相加的和是" + sum);
    </script>
</body>
</html>